"""Config flow to configure esphome component."""
from collections import OrderedDict
from typing import Optional

import voluptuous as vol

from homeassistant import config_entries
from homeassistant.helpers import ConfigType

from .entry_data import DATA_KEY, RuntimeEntryData


@config_entries.HANDLERS.register("esphome")
class EsphomeFlowHandler(config_entries.ConfigFlow):
    """Handle a esphome config flow."""

    VERSION = 1
    CONNECTION_CLASS = config_entries.CONN_CLASS_LOCAL_PUSH

    def __init__(self):
        """Initialize flow."""
        self._host: Optional[str] = None
        self._port: Optional[int] = None
        self._password: Optional[str] = None

    async def async_step_user(
        self, user_input: Optional[ConfigType] = None, error: Optional[str] = None
    ):
        """Handle a flow initialized by the user."""
        if user_input is not None:
            return await self._async_authenticate_or_add(user_input)

        fields = OrderedDict()
        fields[vol.Required("host", default=self._host or vol.UNDEFINED)] = str
        fields[vol.Optional("port", default=self._port or 6053)] = int

        errors = {}
        if error is not None:
            errors["base"] = error

        return self.async_show_form(
            step_id="user", data_schema=vol.Schema(fields), errors=errors
        )

    @property
    def _name(self):
        return self.context.get("name")

    @_name.setter
    def _name(self, value):
        # pylint: disable=unsupported-assignment-operation
        self.context["name"] = value
        self.context["title_placeholders"] = {"name": self._name}

    def _set_user_input(self, user_input):
        if user_input is None:
            return
        self._host = user_input["host"]
        self._port = user_input["port"]

    async def _async_authenticate_or_add(self, user_input):
        self._set_user_input(user_input)
        error, device_info = await self.fetch_device_info()
        if error is not None:
            return await self.async_step_user(error=error)
        self._name = device_info.name

        # Only show authentication step if device uses password
        if device_info.uses_password:
            return await self.async_step_authenticate()

        return self._async_get_entry()

    async def async_step_discovery_confirm(self, user_input=None):
        """Handle user-confirmation of discovered node."""
        if user_input is not None:
            return await self._async_authenticate_or_add(None)
        return self.async_show_form(
            step_id="discovery_confirm", description_placeholders={"name": self._name}
        )

    async def async_step_zeroconf(self, user_input: ConfigType):
        """Handle zeroconf discovery."""
        # Hostname is format: livingroom.local.
        local_name = user_input["hostname"][:-1]
        node_name = local_name[: -len(".local")]
        address = user_input["properties"].get("address", local_name)

        # Check if already configured
        for entry in self._async_current_entries():
            already_configured = False
            if entry.data["host"] == address:
                # Is this address already configured?
                already_configured = True
            elif entry.entry_id in self.hass.data.get(DATA_KEY, {}):
                # Does a config entry with this name already exist?
                data: RuntimeEntryData = self.hass.data[DATA_KEY][entry.entry_id]
                # Node names are unique in the network
                if data.device_info is not None:
                    already_configured = data.device_info.name == node_name

            if already_configured:
                return self.async_abort(reason="already_configured")

        self._host = address
        self._port = user_input["port"]
        self._name = node_name

        # Check if flow for this device already in progress
        for flow in self._async_in_progress():
            if flow["context"].get("name") == node_name:
                return self.async_abort(reason="already_configured")

        return await self.async_step_discovery_confirm()

    def _async_get_entry(self):
        return self.async_create_entry(
            title=self._name,
            data={
                "host": self._host,
                "port": self._port,
                # The API uses protobuf, so empty string denotes absence
                "password": self._password or "",
            },
        )

    async def async_step_authenticate(self, user_input=None, error=None):
        """Handle getting password for authentication."""
        if user_input is not None:
            self._password = user_input["password"]
            error = await self.try_login()
            if error:
                return await self.async_step_authenticate(error=error)
            return self._async_get_entry()

        errors = {}
        if error is not None:
            errors["base"] = error

        return self.async_show_form(
            step_id="authenticate",
            data_schema=vol.Schema({vol.Required("password"): str}),
            description_placeholders={"name": self._name},
            errors=errors,
        )

    async def fetch_device_info(self):
        """Fetch device info from API and return any errors."""
        from aioesphomeapi import APIClient, APIConnectionError

        cli = APIClient(self.hass.loop, self._host, self._port, "")

        try:
            await cli.connect()
            device_info = await cli.device_info()
        except APIConnectionError as err:
            if "resolving" in str(err):
                return "resolve_error", None
            return "connection_error", None
        finally:
            await cli.disconnect(force=True)

        return None, device_info

    async def try_login(self):
        """Try logging in to device and return any errors."""
        from aioesphomeapi import APIClient, APIConnectionError

        cli = APIClient(self.hass.loop, self._host, self._port, self._password)

        try:
            await cli.connect(login=True)
        except APIConnectionError:
            await cli.disconnect(force=True)
            return "invalid_password"

        return None
